Led package structure

ABSTRACT

An LED package structure includes a base, an LED chip disposed on the base, at least one metal wire, a phosphor sheet, and an encapsulation resin disposed in the base and encapsulating the LED chip, the metal wire, and the phosphor sheet. The LED chip has at least one electrode thereon. The metal wire has an apex and a loop height being defined by the apex. The metal wire is electrically connected to the electrode and the base. The phosphor sheet includes a B-stage resin and a plurality of phosphor powders mixed therewith. The phosphor sheet is adhered to the LED chip by the B-stage resin capable of viscosity and covers the top surface, the side surface, and the electrode of the LED chip. A thickness of the phosphor sheet is smaller than the loop height, and the apex of the metal wire is exposed from the phosphor sheet.

The present application is a divisional application of co-pendingapplication Ser. No. 14/818,355, filed on Aug. 5, 2015 and entitled “LEDPACKAGE STRUCTURE AND MANUFACTURING METHOD THEREOF”, now allowed.Moreover, this divisional application contains claims based on InventionH, according to the Restriction Requirement dated Mar. 23, 2016.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The instant invention relates to an LED package structure; inparticular, to an LED package structure that incorporates with aphosphor sheet.

2. Description of Related Art

Currently, applying the phosphor on the LED chip includes a dispensingmethod and a spray coating method. In the dispensing method, theproblems of precipitation of phosphor powder and bad distribution of theCIE coordinate are happened to the LED package structure. In the spraycoating method, a non-essential portion (e.g., a metal wire or an innersurface of base of the LED package structure), which does not need to beprovided with any phosphor, is coated with the phosphor, such that theproblems of low utilization of phosphor powder and the use of a toluenesolvent, which is not environmentally friendly, are happened to the LEDpackage structure.

SUMMARY OF THE INVENTION

The instant disclosure provides an LED package structure and amanufacturing method thereof, which incorporates a phosphor sheet withan LED chip that is electrically connected by wire bonding foreffectively solving the problems of precipitation of phosphor powder,low utilization of phosphor powder, and the use of toluene solvent.

In summary, the phosphor sheet of the instant disclosure is configuredto cover the outer surface of the LED chip and the electrode of the LEDchip, so the LED chip can be provided without any light leakage by usingthe phosphor sheet, thereby avoiding the LED package structure beingmanufactured with bad color uniformity.

In order to further appreciate the characteristics and technicalcontents of the instant invention, references are hereunder made to thedetailed descriptions and appended drawings in connection with theinstant invention. However, the appended drawings are merely shown forexemplary purposes, rather than being used to restrict the scope of theinstant invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are perspective views showing step S110 of amanufacturing method of an LED package structure according to theinstant disclosure;

FIG. 2 is a perspective view showing step S120 of the manufacturingmethod of the LED package structure;

FIGS. 3A, 3B and 3C are perspective views showing step S130 of themanufacturing method of the LED package structure;

FIGS. 4A and 4B are perspective views showing step S140 of themanufacturing method of the LED package structure;

FIGS. 5A and 5B are perspective views showing step S150 of themanufacturing method of the LED package structure;

FIG. 5C is a perspective view of the LED package structure having a softfirst phosphor sheet;

FIGS. 6A and 6B are perspective views showing step S160 of themanufacturing method of the LED package structure;

FIG. 6C is an exploded view of FIG. 6A without the encapsulation resin;

FIG. 7A is a perspective view showing the LED package having the metalwires with a reverse loop;

FIG. 7B is a perspective view showing the LED package having the metalwires with a square loop;

FIG. 8 is a perspective view showing step S230 of the manufacturingmethod of the LED package structure;

FIG. 9 is a perspective view showing step S240 of the manufacturingmethod of the LED package structure;

FIG. 10A is a perspective view showing step S250 of the manufacturingmethod of the LED package structure; and

FIG. 10B is a perspective view of the LED package structure having asoft first phosphor sheet and a soft second phosphor sheet.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

Please refer to FIGS. 1A through 7B, which show a first embodiment ofthe instant disclosure. References are hereunder made to the detaileddescriptions and appended drawings in connection with the instantinvention. However, the appended drawings are merely shown for exemplarypurposes, rather than being used to restrict the scope of the instantinvention.

The instant embodiment provides a manufacturing method of an LED packagestructure. The manufacturing method includes the following steps S110 toS160. The following description discloses each step with reference tothe corresponding figure.

Please refer to FIGS. 1A and 1B. In Step S110, a base 1 is provided, andthe base 1 in the instant disclosure is a bowl construction for example.The base 1 has a reflecting body 11 and a pair of lead frames. The pairof lead frames includes a first lead frame 12 a and a second lead frame12 b arranged apart from each other and partially embedded in thereflecting body 11. The size of the first lead frame 12 a is larger thanthat of the second lead frame 12 b. An accommodating space 13 can becooperatively defined by the reflecting body 11 and the first and secondlead frames 12 a, 12 b. The first and second lead frames 12 a, 12 bexposed from the reflecting body 11 can be the bottom portion of theaccommodating space 13. The first and second lead frames 12 a, 12 b arequad-flat no-lead (QFN) lead frames, and the proportion of the firstlead frame 12 a exposed from the reflecting body 11 to the bottomportion of the accommodating space 13 is greater than 50%. Twopenetrating holes formed on the first and second lead frames 12 a, 12 bare provided for being firmly fixed the reflecting body 11 with thefirst and second lead frames 12 a, 12 b. The base 1 of the instantembodiment is just an example, and it is not limited to the figures.

And then, at least one LED chip 2 is disposed on the base 1. The LEDchip 2 includes a top surface 21, a bottom surface 22, and a sidesurface 23 arranged between the top surface 21 and the bottom surface22. The LED chip 2 in the instant embodiment is a horizontal chip, whichmeans that two electrodes 24 of the LED chip 2 are arranged on the topsurface 21 of the LED chips and are spaced apart from each other. TheLED chip 2 is arranged in the accommodating space 13 and the bottomsurface 22 of the LED chip 2 is fixed on the lead frame 12 a of the base1.

After that, the two electrodes 24 of the LED chip 2 are electricallyconnected to the two lead frames 12 a, 12 b of the base 1 by two metalwires 3. Specifically, one end of one of the two metal wires 3 isconnected to the one of two electrodes 24 of the LED chip 2, and theother end of one of the two metal wires 3 is connected to one of thefirst and second lead frames 12 a, 12 b of the base 1. One end of theother one of the two metal wires 3 is connected to the other one of twoelectrodes 24 of the LED chip 2, and the other end of the other one ofthe two metal wires 3 is connected to the other one of the first andsecond lead frames 12 a, 12 b of the base 1. Therefore, the LED chip 2can be electrically connected to the two lead frames 12 a, 12 b of thebase 1 by the two metal wires 3.

Moreover, each of the metal wires 3 has a parabolic shape, and each ofthe metal wires 3 has an apex 31 arranged at a turning point of theparabolic shape. A height between the bottom portion of theaccommodating space 13 and the apex 31 is greater than a height betweenthe bottom portion of the accommodating space 13 and the top surface 21of the LED chip 2 (i.e., the thickness of the LED chip 2), and a heightbetween the apex 31 and the top surface 21 of the LED chip 2 is definedas a loop height H. The loop height H of the metal wire 3 bonding byforward bonding for the square loop in the instant embodiment is greaterthan 6 mil.

In addition, the LED chip 2 in the instant embodiment is a horizontalchip for example. However, the LED chip 2 also can be a vertical chip inanother non-shown embodiment. Specifically, when the LED chip (notshown) is the vertical chip, the top surface and the bottom surface ofthe LED chip respectively have an electrode thereon. The LED chip isarranged in the accommodating space, the electrode arranged on thebottom surface of the LED chip is electrically connected to one of thelead frames, and the electrode arranged on the top surface of the LEDchip is electrically connected to another lead frame by a metal wire.

Please refer to FIG. 2. In Step S120, a glue 4 is disposed on the topsurface 21 of the LED chip 2, the glue 4 in the instant embodiment isdisposed on the top surface 21 of the LED chip 2 by a dispensing method,and the glue 4 is approximately arranged on the center of the topsurface 21 of the LED chip 2, but is not limited thereto. The viscosityof the glue 4 is smaller than 10000 cP, the refractive index of the glue4 with respect to light having a wavelength of 532 nm is 1.54, and theglue 4 in the instant embodiment is a phenylsiloxane resin capable oflow viscosity for example. The glue 4 formed on the LED chip 2 has athickness of about 100 μm, and the amount of the glue 4 is approximatelyequal to the area of the top surface 21 of the LED chip 2 multiplied bythe thickness of the glue 4.

Please refer to FIGS. 3A through 3C. In Step S130, a first phosphorsheet 5, which has a thickness Ti smaller than the loop height H, ischosen to flatly dispose on the apexes 31 of the two metal wires 3. Thefirst phosphor sheet 5 is formed by mixing a plurality of first phosphorpowders (not labeled) with a B-stage resin (not labeled), and theB-stage resin can be softened by heating. Moreover, the viscosity of theB-stage resin is smaller than 10000 cP, the refractive index of theB-stage resin with respect to light having a wavelength of 532 nm is1.56, and the B-stage resin in the instant embodiment is aphenylsiloxane resin capable of low viscosity for example.

Specifically, the first phosphor sheet 5 provided by the instantembodiment does not need to have any receiving hole for receiving theelectrodes 24 of the LED chip 2. The area of the first phosphor sheet 5is preferably larger than a sum of the area of the top surface 21 andthe area of the side surface 23 of the LED chip 2. When the firstphosphor sheet 5 is disposed on the apexes 31 of the two metal wires 3,the LED chip 2 is entirely disposed within a region of the base 1defined by orthogonally projecting the first phosphor sheet 5 onto thebottom portion of the accommodating space 13, and structural strength ofthe two metal wires 3 must be strong enough to support the firstphosphor sheet 5 without any deformation. Namely, the structuralstrength of the two metal wires 3 is larger than that of the firstphosphor sheet 5.

In order to clearly explain the following step S140, the first phosphorsheet 5 is pressed downwardly to adhere to the LED chip 2 that iselectrically connected to a pair of lead frames 12 a, 12 b by bonding atleast one wire 3. Specifically, the first phosphor sheet 5 can bedefined as a bonding portion 51 arranged on the center thereof and abent portion 52 arranged outside the bonding portion 51. The bondingportion 51 is substantially arranged above the center portion of the topsurface 21 of the LED chip 2 and arranged between the electrodes 24 ofthe LED chip 2. That is to say, the glue 4 is arranged under the bondingportion 51, and a portion of the first phosphor sheet 5 excluding thebonding portion 51 is the bent portion 52.

Please refer to FIGS. 4A and 4B. In Step S140, the bonding portion 51 ofthe first phosphor sheet 5 arranged between the two electrodes 24 of theLED chip 2 is pressed toward the top surface 21 of the LED chip 2 toadhere to the top surface 21 of the LED chip 2. The bent portion 52abuts against the two metal wires 3 so as to be bent during the pressingof the bonding portion 51. Thus, the glue 4 is squeezed and flowsoutwardly along the top surface 21 and the side surface 23 by thebonding portion 51 of the first phosphor sheet 5, thus the glue 4 isformed as a layer construction covering the top surface 21 and the sidesurface 23 of the LED chip 2. When the amount of the glue 4 is too much,the glue 4 will further flow to the bottom of the LED chip 2 or thebottom portion of the accommodating space 13. The thickness of the layerconstruction of the glue 4 in the instant embodiment is smaller than 1mm.

The structural strength of the two metal wires 3 must be strong enoughto bend the bent portion 52 without any deformation during the pressingof the bonding portion 51. Moreover, when the bonding portion 51 of thefirst phosphor sheet 5 arranged between the two electrodes 24 of the LEDchip 2 abuts against the center portion of the top surface 21 of the LEDchip 2, the bonding portion 51 of the first phosphor sheet 5 is adheredto the center portion of the top surface 21 by the property of viscositythereof. Furthermore, the bonding portion 51 and the center portion ofthe top surface 21 can be combined more firmly by the glue 4 when theglue 4 is disposed on the top surface 21 of the LED chip 2.

Please refer to FIGS. 5A and 5B. In Step S150, a baking process isimplemented to heat the first phosphor sheet 5 (i.e., in a heatingcondition about 50˜80° C.), such that the first phosphor sheet 5 issoftened to flow along the top surface 21 and the side surface 23,and/or further to flow to the bottom portion of the accommodating space13, thereby entirely covering the top surface 21, the side surface 23,and the electrodes 24 of the LED chip 2 and/or covering the bottomportion of the accommodating space 13 (as shown in FIG. 5B). And then,the softened first phosphor sheet 5 is solidified to cover the LED chip2.

Additionally, when the phosphor sheet bonded on the LED chip 2 is chosenby different hardness, the phosphor sheets will be formed into differentshapes. As shown in FIG. 5B, when a hard first phosphor sheet 5 isapplied on the LED chip 2, the shape of the first phosphor sheet 5 iscorresponding to the shape of the LED chip 2, so the first phosphorsheet 5 is solidified to form as a step construction, thus the firstphosphor sheet 5 is configured as a cover to entirely shield the LEDchip 2. As shown in FIG. 5C, when a soft first phosphor sheet 5 isapplied on the LED chip 2, the shape of the first phosphor sheet 5 isnot corresponding to the shape of the LED chip 2, the first phosphorsheet 5 is solidified to form as a hemisphere construction, thus firstphosphor sheet 5 is configured to entirely shield the LED chip 2. Basedon the above description, the first phosphor sheet 5 is formed by mixingthe first phosphor powders with the B-stage resin, so the hardness ofthe first phosphor sheet 5 can be adjusted by changing the compositionof the B-stage resin.

Specifically, the softened first phosphor sheet 5 in melt state flowsalong the outer surface of the LED chip 2, so the apexes 31 of the metalwires 3 are exposed from the first phosphor sheet 5. When the parabolicshape of the metal wire 3 has a precipitous slope (for example, themetal wire 3 is a Q loop as shown in FIG. 5A) in comparison to the topsurface 21 of the LED chip 2, the flowing of the softened first phosphorsheet 5 in melt state will be influenced by the metal wires 3.Accordingly, the glue 4 capable of the viscosity lower than 10000 cP canbe chosen to improve the flowing of the soften first phosphor sheet 5,thereby the top surface 21, the two electrodes 24, and the side surface23 of the LED chip 2 can be uniformly and entirely covered by the firstphosphor sheet 5. A covering state can be defined by that the LED chip 2is covered by the first phosphor sheet 5 after the baking process. Whenthe first phosphor sheet 5 is in the covering state, a height betweenthe top surface of the first phosphor sheet 5 and the bottom portion ofthe accommodating space 13 is smaller than a height between the apex 31and the bottom portion of the accommodating space 13. That is to say,the apex 31 of the metal wires 3 is exposed from the first phosphorsheet 5.

Please refer to FIGS. 6A and 6B. In Step S160, an encapsulation resin 7is arranged in the accommodating space 13 of the base 1 to encapsulatethe LED chip 2, the metal wires 3, and the first phosphor sheet 5,whereby an LED package structure 100 has been prepared. Moreover, in theinstant embodiment, the LED chip 2 of the LED package structure 100 isconfigured to emit blue light, the first phosphor sheet 5 has yellowphosphor powders, so the blue light emitted from the LED chip 2 can betransformed into white light after passing through the first phosphorsheet 5.

Additionally, the instant disclosure takes the above steps S110˜S160 asan example, but the steps S110˜S160 can be adjusted to differentrequests, such as the following description.

As shown in FIG. 7A, when the parabolic shape of the metal wire 3 has aflat slope (for example, the metal wire 3 is a reverse loop as shown inFIG. 7A) in comparison to the top surface 21 of the LED chip 2, theflowing of the softened first phosphor sheet 5 in melt state is slightlyinfluenced by the metal wires 3. Thus, the glue 4 is not needed to beused, and the step S140 of adhering the bonding portion 51 of the firstphosphor sheet 5 to the top surface 21 of the LED chip 2 is just by theviscosity thereof, so that the step S120 of disposing the glue 4 can beomitted. The loop height H of the metal wire 3 for the reverse loop isdefined by a height between the apex 31 of the metal wire 3 and thebottom portion of the accommodating space 13 (e.g., one end of the metalwire 3 is connected to the base 1), and the loop height H of the metalwire 3 bonding by reverse bonding for the reverse loop in the instantembodiment is smaller than 6 mil. Moreover, the metal wire 3 can be asquare loop as shown in FIG. 7B. The apex 31 of the metal wire 3 asshown in FIGS. 7A and 7B is arranged above the lead frame 12 b, and notarranged above the LED chip 2, thus when the first phosphor sheet 5 isin the bending mode (i.e., in a condition of a bonding portion 51 of thefirst phosphor 5 sheet is adhered to the LED chip 2, and a bent portion52 of the first phosphor sheet 5 is bent by abutting against the atleast one metal wire 3), the apex 31 of the metal wire 3 is notcontacted with the first phosphor sheet 5.

After the appropriate first phosphor sheet 5 is chosen, the bondingportion 51 of the first phosphor sheet 5 is directly pressed toward thetop surface 21 of the LED chip 2 to adhere the first phosphor sheet 5onto the top surface 21 of the LED chip. Therefore, the step ofdisposing the first phosphor sheet 5 on the apexes 31 of the two metalwires 3 can be omitted due to the appropriate choice of the firstphosphor sheet 5.

The manufacturing method of the LED package structure 100 is disclosedin the above description, and the LED package structure 100 prepared bythe above manufacturing method is disclosed thereafter.

Please refer to FIGS. 6A through 6C, which show an LED package structure100. The LED package structure 100 includes a base 1, an LED chip 2disposed on the base 1, at least one metal wire 3 electrically connectedthe LED chip 2 to the base 1, a first phosphor sheet 5 covering the LEDchip 2, a glue 4 arranged on the LED chip 2 for adhering the firstphosphor sheet 5, and an encapsulation resin 7.

The base 1 in the instant disclosure is a bowl construction for example.The base 1 has a reflecting body 11 and a pair of lead frames 12 a, 12 barranged apart from each other and partially embedded in the reflectingbody 11. An accommodating space 13 can be cooperatively defined by thereflecting body 11 and the pair of lead frames 12 a, 12 b. Part of thepair of lead frames 12 a, 12 b can be formed as the bottom portion ofthe accommodating space 13. However, the base 1 of the instantembodiment is not limited to the figures.

The LED chip 2 includes a top surface 21, a bottom surface 22, and aside surface 23 arranged between the top surface 21 and the bottomsurface 22. The LED chip 2 in the instant embodiment is a horizontalchip, so the top surface 21 of the LED chip 2 has two electrodes 24arranged apart from each other. The bottom surface 22 of the LED chip 2is fixed on the first lead frame 12 a of the base 1 and is arranged inthe accommodating space 13. The LED chip 2 in the instant embodiment isa horizontal chip for example, but the LED chip 2 can be a vertical chipin another non-shown embodiment. Specifically, when the LED chip (notshown) is the vertical chip, the top surface and the bottom surface ofthe LED chip each has an electrode. The LED chip is arranged in theaccommodating space, the electrode arranged on the bottom surface of theLED chip is electrically connected to one of the lead frames, and theelectrode arranged on the top surface of the LED chip is electricallyconnected to another lead frame by at least one metal wire.

One end of the metal wire 3 is respectively connected to the electrode24 of the LED chip 2, and the other end of the metal wire 3 is connectedto the one of the first and second lead frames 12 a, 12 b of the base 1.Moreover, the metal wire 3 has a parabolic shape, and an apex 31 of themetal wire 3 is arranged at a turning point of the parabolic shape. Aheight between the bottom portion of the accommodating space 13 and theapex 31 is greater than a height between the bottom portion of theaccommodating space 13 and the top surface 21 of the LED chip 2 (i.e.,the thickness of the LED chip 2), and a height between the apex 31 andthe top surface 21 of the LED chip 2 is defined as a loop height H. Theloop height H of the metal wire 3 bonded by forward bonding for thesquare loop in the instant embodiment is greater than 6 mil.

The first phosphor sheet 5 is formed by mixing a plurality of firstphosphor powders (not labeled) with a B-stage resin (not labeled), andthe B-stage resin can be softened in melt state by heating. Moreover,the viscosity of the B-stage resin is smaller than 10000 cP, therefractive index of the B-stage resin with respect to light having awavelength of 532 nm is 1.56, and the B-stage resin in the instantembodiment is a phenylsiloxane resin capable of low viscosity forexample. The top surface 21, the side surface 23, the two electrodes 24of the LED chip 2, and/or a portion of the bottom portion of theaccommodating space 13 arranged close to the LED chip 2 are entirelycovered by the first phosphor sheet 5. When the LED chip 2 is covered bythe first phosphor sheet 5 (i.e., in the covering state), the apex 31 isexposed from the first phosphor sheet 5 in the covering state.

The viscosity of the glue 4 is smaller than 10000 cP, the refractiveindex of the glue 4 with respect to light having a wavelength of 532 nmis 1.54, and the glue 4 in the instant embodiment is a phenylsiloxaneresin capable of low viscosity for example. Moreover, the glue 4 isarranged on the LED chip 2 for adhering the first phosphor sheet 5 ontothe LED chip 2, so the first phosphor sheet 5 can be firmly adhered tothe LED chip 2 by the glue 4. If the first phosphor sheet 5 can befirmly adhered to the LED chip 2 by the physical property of viscositythereof, the glue 4 can be omitted.

The encapsulation resin 7 is arranged in the accommodating space 13 ofthe base 1 by a dispensing method or a molding method, and the LED chip2, the metal wires 3, and the first phosphor sheet 5 can be encapsulatedby the encapsulation resin 7.

Second Embodiment

Please refer to the FIGS. 8 through 10B, which show a second embodimentof the instant disclosure. The second embodiment is similar to the firstembodiment, so the same features are not disclosed again (i.e., thesteps S210, S220, S260 of the second embodiment are respectivelyidentical to the steps S110, S120, S160 of the first embodiment). Themain difference of the two embodiments is that the second embodimentadding a second phosphor sheet 6 therein. In order to clearly disclosethe said different feature, the figures of the second embodiment arecross-sectional views to clearly show the different feature, and thedifferent feature is disclosed as follows.

Please refer to FIG. 8. In Step S230, a thickness T2 of the firstphosphor sheet 5 and a second phosphor sheet 6, which is smaller thanthe loop height H, are chosen. The second phosphor sheet 6 is disposedon the first phosphor sheet 5, and the first phosphor sheet 5 and thesecond phosphor sheet 6 are flatly disposed on the apexes 31 of the twometal wires 3. The second phosphor sheet 6 is formed by mixing aplurality of second phosphor powders (not labeled) with a B-stage resin(not labeled), and the B-stage resin can be softened in melt state byheating. The physical property of the second phosphor sheet 6 isdifferent from that of the first phosphor sheet 5. For example, theoptical property of the second phosphor sheet 6 is different from thatof the first phosphor sheet 5. In other words, the material, theconcentration of phosphor powder, and the thickness of the secondphosphor sheet 6 are different from that of the first phosphor sheet 5.Moreover, the material of the resin of the second phosphor sheet 6 issubstantially identical to that of the resin of the first phosphor sheet5.

Specifically, the receiving hole of the second phosphor sheet 6 in theinstant embodiment is not needed to be provided for receiving theelectrodes 24 of the LED chip 2. The area of the second phosphor sheet 6is preferably larger than a sum area of the top surface 21 and the sidesurface 23 of the LED chip 2. When the first phosphor sheet 5 and thesecond phosphor sheet 6 are disposed on the apexes 31 of the two metalwires 3, the LED chip 2 is entirely disposed within a region of the base1 defined by orthogonally projecting the first phosphor sheet 5 and thesecond phosphor sheet 6 onto the bottom portion of the accommodatingspace 13. Specifically, the structural strength of the two metal wires 3must be strong enough to support the first phosphor sheet 5 and thesecond phosphor sheet 6 without any deformation.

Moreover, a bonding portion 61 of the second phosphor sheet 6 arrangedon the center thereof and a bent portion 62 arranged outside the bondingportion 61 (as shown in FIG. 9) can be defined when the second phosphorsheet 6 is pressed to be a bending mode. The bonding portion 61 isapproximately arranged above the center portion of the top surface 21 ofthe LED chip 2 and arranged between the electrodes 24 of the LED chip 2.That is to say, the glue 4 is arranged under the bonding portion 61, anda portion of the second phosphor sheet 6 excluding the bonding portion61 is the bent portion 62.

Please refer to FIG. 9. In Step S240, the bonding portion 61 of thesecond phosphor sheet 6 is pressed to move the two bonding portions 51,61 toward the top surface 21 of the LED chip 2, thus the bonding portion51 is adhered to the top surface 21 of the LED chip and the two bondingportions 51, 61 are arranged between the two electrodes 24 of the LEDchip 2. The bent portions 52, 62 abut against the two metal wires 3 soas to be bent with respect to the bonding portions 51, 61 during thepressing of the bonding portion 61. Thus, the glue 4 is squeezed andoutwardly flows along the top surface 21 and the side surface 23 of theLED chip 2 by the bonding portion 51 of the first phosphor sheet 5, andthe glue 4 further flows to the bottom of the LED chip 2 or the bottomportion of the accommodating space 13 when the amount of the glue 4 ismuch enough.

The structural strength of the two metal wires 3 must be strong enoughto bend the bent portions 52, 62 without any deformation during thepressing of the bonding portion 61. Moreover, when the bonding portion51 abuts against a center portion of the top surface 21 arranged betweenthe two electrodes 24 of the LED chip 2, the bonding portion 51 isadhered to the portion of the top surface 21 of the LED chip 2 by thephysical property of viscosity thereof, and the bonding portion 51 andthe center portion of the top surface 21 can be combined more firmly bythe glue 4.

Please refer to FIG. 10A, In Step S250, a baking process is implementedto heat the first phosphor sheet 5 and the second phosphor sheet 6(i.e., a heating condition about 50˜80° C.), such that the firstphosphor sheet 5 and the second phosphor sheet 6 are softened in meltstate and flows along the top surface 21 and the side surface 23, andfurther to the bottom portion of the accommodating space 13, therebyentirely covering the top surface 21, the side surface 23, and theelectrodes 24 of the LED chip 2 and further covering the bottom portionof the accommodating space 13. And then, the softened first phosphorsheet 5 and the second phosphor sheet 6 in melt state are solidified tocover the LED chip 2. Moreover, the first phosphor powders of the firstphosphor sheet 5 are arranged at the inner side of the second phosphorpowders of the second phosphor sheet 6.

Specifically, the softened first and second phosphor sheets 5, 6 in meltstate flow along the outer surface of the LED chip 2, so that the apexes31 of the metal wires 3 are not adhered by the phosphor powders. Inother words, when the LED chip 2 is covered by the first and secondphosphor sheets 5, 6 (i.e., in the covering state), a height between thetop surface of the first phosphor sheet 5 and the bottom portion of theaccommodating space 13 is smaller than a height between the apex 31 andthe bottom portion of the accommodating space 13. That is to say, theapexes 31 of the metal wires 3 are exposed from the first phosphor sheet5.

Additionally, when the parabolic shape of the metal wire 3 has aprecipitous slope (i.e., the metal wire 3 has a shape of Q loop) incomparison to the top surface 21 of the LED chip 2, the flowing of thesoftened first and second phosphor sheets 5, 6 in melt state isinfluenced by the metal wires 3. Accordingly, the glue 4 can be used toimprove the flowing of the softened first and second phosphor sheets 5,6 in melt state, thereby the top surface 21, the two electrodes 24, andthe side surface 23 of the LED chip 2 are uniformly and entirely coveredby the first and second phosphor sheets 5, 6. Moreover, when the LEDchip 2 is covered by the first and second phosphor sheets 5, 6 (i.e., inthe covering state), a height between the top surface of the secondphosphor sheet 6 and the bottom portion of the accommodating space 13 issmaller than a height between the apex 31 and the bottom portion of theaccommodating space 13. That is to say, the apex 31 of the metal wire 3is exposed from the first phosphor sheet 5 and the second phosphor sheet6.

In addition, when the phosphor sheet bonded on the LED chip 2 is chosenwith different hardness, the phosphor sheets can be formed intodifferent shapes due to the different hardness. As shown in FIG. 10A,when a hard first phosphor sheet 5 and a hard second phosphor sheet 6are applied to the LED chip 2, the flowing of the first phosphor sheet 5and the second phosphor sheet 6 is corresponding to the shape of the LEDchip 2, so the first phosphor sheet 5 and the second phosphor sheet 6are solidified to form as a step construction. As shown in FIG. 10B,when a soft first phosphor sheet 5 and a soft second phosphor sheet 6are applied to the LED chip 2, the flowing of the first phosphor sheet 5and the second phosphor sheet 6 is not corresponding to the shape of theLED chip 2. The first phosphor sheet 5 and the second phosphor sheet 6are solidified to form as a hemisphere construction. Based on the abovedescription, each of the first phosphor sheet 5 and the second phosphorsheet 6 is formed by mixing the phosphor powders with the B-stage resin,so the hardness of the first phosphor sheet 5 and the second phosphorsheet 6 can be respectively adjusted by changing the composition of theB-stage resin. It should be noted that, when the total thickness T2 ofthe first and second phosphor sheets 5, 6 is close to the loop height H,the apex 31 may be climbed by the B-stage resin mixed with the phosphorpowders of the first and second phosphor sheets 5, 6 due to thecapillarity, so that the apex 31 of the metal wire 3 may be adhered withsome of the phosphor powders thereon. However, the apex 31 of the metalwire 3 is substantially exposed from the first and second phosphorsheets 5, 6.

Moreover, in the instant embodiment, the first phosphor sheet 5 hasyellow phosphor powders and the second phosphor sheet 6 has red phosphorpowders, so the blue light emitted from the LED chip 2 can betransformed into white light after passing through the first phosphorsheet 5 and the second phosphor sheet 6. Accordingly, the LED packagestructure 100 has a light property of high color rendering index (CRI).

The manufacturing method of the LED package structure 100 of the secondembodiment has disclosed in above description, and the LED packagestructure 100 prepared by the above manufacturing method of the secondembodiment is also disclosed in the following description. The LEDpackage structure 100 of the second embodiment is similar to the LEDpackage structure 100 of the first embodiment, so the same features arenot disclosed again. As shown in FIG. 8, the main difference of the twoembodiments is that the first phosphor powders of the first phosphorsheet 5 is arranged at the inner side of the second phosphor powders ofthe second phosphor sheet 6.

[The Possible Effect of the Instant Disclosure]

In summary, the phosphor sheet of the instant disclosure is configuredto cover the outer surface and the electrode of the LED chip, so byusing the phosphor sheet, the LED chip can be provided without any lightleakage, thereby avoiding the LED package structure being manufacturedwith bad color uniformity. The B-stage phosphor sheet of the instantdisclosure is provided without any receiving hole, so that the phosphorsheet of the instant disclosure is prepared more easily than theconventional phosphor sheet.

Moreover, when the phosphor sheet cooperating with the LED chip that iselectrically connected by wire bonding is applied to the base having abowl construction the effect of high utilization of phosphor powder isfacilitated and a problem of precipitation of phosphor powder isimproved in this instant disclosure. Accordingly, a CIE measuringmechanism can be incorporated with the phosphor sheet firstly beforedisposing the phosphor sheet onto the LED chip, such that the CIE indexcan be smaller than one SCDM (Standard Deviation Color Matching)

Additionally, a plurality of phosphor sheets respectively havingdifferent light properties can be used for the manufacturing method ofthe LED package structure so as to control the color temperature of theLED package structure.

The descriptions illustrated supra set forth simply the preferredembodiments of the instant invention; however, the characteristics ofthe instant invention are by no means restricted thereto. All changes,alterations, or modifications conveniently considered by those skilledin the art are deemed to be encompassed within the scope of the instantinvention delineated by the following claims.

What is claimed is:
 1. An LED package structure, comprising: a base; an LED chip having at least one electrode thereon and being disposed on the base, the LED chip including a top surface, a bottom surface, and a side surface arranged between the top surface and the bottom surface; at least one metal wire having an apex and a loop height being defined by the apex, two opposite ends of the at least one metal wire being respectively and electrically connected to the at least one electrode of the LED chip and the base; a first phosphor sheet including a B-stage resin and a plurality of phosphor powders being mixed therewith, the first phosphor sheet being adhered to the LED chip by the B-stage resin capable of viscosity and covering the top surface, the side surface, and the at least one electrode of the LED chip, wherein a thickness of the first phosphor sheet is smaller than the loop height, and the apex of the at least one metal wire is exposed from the first phosphor sheet; and an encapsulation resin disposed in the base and encapsulating the LED chip, the at least one metal wire, and the first phosphor sheet.
 2. The LED package structure as claimed in claim 1, wherein the at least one metal wire connects the at least one electrode of the LED chip to the base by reverse bonding, the loop height is a height between the apex of the at least one metal wire and a bonding point of the base, and the loop height is smaller than 6 mil.
 3. The LED package structure as claimed in claim 1, wherein the at least one metal wire connects the at least one electrode of the LED chip to the base by forward bonding, the loop height is a height between the apex of the at least one metal wire and the top surface of the LED chip, the loop height is greater than 6 mil.
 4. The LED package structure as claimed in claim 3, further comprising a glue disposed on the top surface of the LED chip, the first phosphor sheet is adhered to the LED chip by the B-stage resin and the glue.
 5. The LED package structure as claimed in claim 4, wherein at least one of the glue and the B-stage resin is a phenylsiloxane resin capable of low viscosity, and the low viscosity of the glue is smaller than 10000 cP.
 6. The LED package structure as claimed in claim 4, wherein the refractive index of the glue with respect to light having a wavelength of 532 nm is 1.54.
 7. The LED package structure as claimed in claim 4, wherein the glue is entirely cladded by the first phosphor sheet.
 8. The LED package structure as claimed in claim 4, wherein the refractive index of the B-stage resin with respect to light having a wavelength of 532 nm is 1.56.
 9. The LED package structure as claimed in claim 4, wherein an amount of the glue is approximately equal to an area of the top surface of the LED chip multiplied by a thickness of the glue.
 10. The LED package structure as claimed in claim 9, wherein the thickness of the glue is approximately 100 μm.
 11. The LED package structure as claimed in claim 1, wherein a shape of the first phosphor sheet is corresponding to a shape of the LED chip, the first phosphor sheet is solidified to form as a step construction, and the first phosphor sheet is configured to entirely shield the LED chip.
 12. The LED package structure as claimed in claim 1, wherein the first phosphor sheet is solidified to form as a hemisphere construction, and the first phosphor sheet is configured to entirely shield the LED chip.
 13. The LED package structure as claimed in claim 1, wherein the apex of the at least one metal wire is not adhered by the phosphor powders.
 14. The LED package structure as claimed in claim 1, further comprising a second phosphor sheet adhered to the first phosphor sheet, wherein an optical property of the first phosphor sheet is different from that of the second phosphor sheet, a total thickness of the first phosphor sheet and the second phosphor sheet is smaller than the loop height, and the apex of the at least one metal wire is exposed from the first and second phosphor sheets.
 15. The LED package structure as claimed in claim 14, wherein the first phosphor sheet and the second phosphor sheet are solidified to form as a step construction corresponding to the shape of the LED chip.
 16. The LED package structure as claimed in claim 15, further comprising a glue disposed on the top surface of the LED chip, the first phosphor sheet is adhered to the LED chip by the B-stage resin and the glue, the glue is entirely cladded by the first phosphor and is formed as a step construction corresponding to the shape of the LED chip.
 17. The LED package structure as claimed in claim 14, wherein the first phosphor sheet and the second phosphor sheet are solidified to form as a hemisphere construction.
 18. The LED package structure as claimed in claim 17, further comprising a glue disposed on the top surface of the LED chip, the first phosphor sheet is adhered to the LED chip by the B-stage resin and the glue, the glue is entirely cladded by the first phosphor and is formed as a step construction corresponding to the shape of the LED chip.
 19. The LED package structure as claimed in claim 1, wherein the base comprises a reflecting body and a pair of lead frames, the pair of lead frames includes a first lead frame and a second lead frame arranged apart from each other and partially embedded in the reflecting body.
 20. The LED package structure as claimed in claim 19, wherein each of the first lead frame and the second lead frame is formed with two penetrating holes for being firmly fixed with the reflecting body. 